JP5922976B2 - Method for producing toner for electrophotography - Google Patents

Description

  The present invention relates to a method for producing an electrophotographic toner, and relates to a method for producing an electrophotographic toner used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method and the like.

In recent years, there has been a demand for a toner having both low-temperature fixability and storability due to speeding up and energy saving of a machine. On the other hand, as a toner production method, an emulsion aggregation method capable of reducing the particle size and separating functions such as a core shell has become mainstream. As binder resins, polyester binder resins having excellent low-temperature fixability have been used instead of styrene-acrylic resins.
Furthermore, in recent toners, attempts have been made to incorporate crystalline polyester (CPES) into the toner as a binder resin in order to achieve further low-temperature fixing. However, it has been known for a long time that CPES emulsions have a very poor stability against flocculants compared to amorphous polyester (APES) emulsions. When forming toner containing CPES, It may be unevenly distributed on the surface of the toner or an aggregate of CPES alone may be formed. As a result, there is a problem that not only sufficient low-temperature fixability cannot be exhibited, but also the heat-resistant storage stability of the toner is deteriorated.

  In response to this problem, means for improving the aggregation stability of an emulsion by copolymerizing a monomer containing a highly polar group such as a sulfonic acid group with polyester and setting the hydrophilicity of CPES high is disclosed (Patent Document). 1). In addition, a binder resin containing a crystalline polyester is phase-inverted and emulsified using a surfactant and an organic solvent, and the surface is coated with a titanium compound, so that it has excellent initial chargeability and admixability, and changes in image density and An electrostatic charge image developing toner capable of suppressing fogging is disclosed (Patent Document 2).

JP 2006-84843 A JP 2011-102892 A

  An object of the present invention is to provide a method for obtaining an electrophotographic toner excellent in low-temperature fixability, charging stability under high temperature and high humidity, and heat-resistant storage stability.

As described above, by incorporating CPES into the toner, it becomes possible to perform ultra-low temperature fixing in an area that cannot be achieved by using amorphous polyester alone. However, as described above, generally, an aqueous dispersion of CPES has very poor aggregation stability. Further, as described in Patent Document 1, when the aqueous dispersion is hydrophilized, the aggregation stability of the CPES emulsion is improved. As a result, the storage stability of the toner can be improved even if CPES is contained. However, on the other hand, since the hydrophilicity of the sulfonic acid group-containing CPES is too high, the hydrophilicity of the toner when used in the toner also increases, and the charging stability and heat resistance of the toner at high temperature and high humidity (HH) are increased. It was found that a new problem that storage stability deteriorates occurred. Therefore, a method for improving the aggregation stability of the CPES emulsion without introducing a highly polar group (hydrophilic group) such as a sulfonic acid group is desired.
On the other hand, as a result of intensive studies, the present inventors have found that when preparing an aqueous dispersion of CPES, the aggregation stability of the aqueous dispersion changes when the addition timing of the surfactant is changed. . It was also found that the above-mentioned problems of electrophotographic toner can be solved at once by using a CPES aqueous dispersion obtained by adding a specific amount of surfactant at a specific addition time. The present invention has been completed based on such knowledge.

The present invention relates to the following method for producing an electrophotographic toner.
An electrophotographic toner manufacturing method comprising particles obtained by fusing agglomerated particles obtained by agglomerating an aqueous dispersion of a binder resin for toner, wherein the binder resin contains a crystalline polyester resin, The aqueous dispersion is obtained through the following steps 1 to 4, and 80 to 100% by weight of the total addition amount of the surfactant is mixed in the steps 2 and 4, and the surfactant is mixed in the steps 2 and 4. A method for producing an electrophotographic toner, wherein the weight ratio of the added amount of the agent is 10/90 to 40/60 as the weight of the surfactant added in Step 2 / the weight of the surfactant added in Step 4.
Step 1: A step of mixing at least a binder resin, an organic solvent and a neutralizing agent to obtain a mixture.
Step 2: A step of mixing at least water and a surfactant with the mixture obtained in Step 1 to obtain a resin dispersion.
Step 3: A step of obtaining an aqueous dispersion of a binder resin by removing the organic solvent from the resin dispersion obtained in Step 2.
Step 4: A step of mixing a surfactant with the aqueous dispersion obtained in Step 3.

  According to the method of the present invention, an electrophotographic toner excellent in low-temperature fixability, charging stability under high temperature and high humidity, and heat-resistant storage stability can be obtained.

Although not all of the details of the effect expression mechanism of the present invention have been elucidated, it is estimated as follows.
In the present invention, CPES can be uniformly taken into the toner by agglomerating using an aqueous dispersion of CPES obtained by adding a predetermined amount of surfactant at a specific addition time. That is, in the process of forming an unstable dispersion of CPES, which is basically unstable, by mixing a specific amount of a surfactant in a specific step, the surfactant can effectively act on the surface of the dispersion. It is considered that an aqueous dispersion having a uniform particle diameter can be formed. As a result, the obtained aqueous dispersion of CPES has less variation in aggregation rate between particles, and uniform aggregated particles can be obtained. In addition, the aggregation speed difference between the amorphous polyester aqueous dispersion and the release agent aqueous dispersion is reduced, and the balance of the aggregation speed is improved, so that CPES is unevenly distributed inside or on the surface of the toner or the aggregation of CPES alone. It is possible to disperse uniformly in the toner without forming a product. As a result, low-temperature fixing is possible due to the sharp melting behavior of the crystalline polyester. Further, it can be presumed that an electrophotographic toner excellent in charging stability and heat-resistant storage stability under high temperature and high humidity can be obtained because CPES is uniformly contained in the toner.
In addition, the action mechanism of the effect expression of this invention is not necessarily limited only to the above estimation mechanism.

The method for producing an electrophotographic toner according to the present invention is a method for producing an electrophotographic toner comprising particles obtained by fusing aggregated particles obtained by aggregating an aqueous dispersion of a binder resin for toner. The binder resin contains a crystalline polyester-based resin, and the aqueous dispersion is obtained through the following steps 1 to 4, and 80 to 100% by weight of the total addition amount of the surfactant is mixed in the steps 2 and 4. And the weight ratio of the addition amount of the surfactant mixed in Step 2 and Step 4 is 10/90 to 40/60 as the weight of the surfactant added in Step 2 / the weight of the surfactant added in Step 4. This is a method for producing an electrophotographic toner.
Step 1: A step of mixing at least a binder resin, an organic solvent and a neutralizing agent to obtain a mixture.
Step 2: A step of mixing at least water and a surfactant with the mixture obtained in Step 1 to obtain a resin dispersion.
Step 3: A step of obtaining an aqueous dispersion of a binder resin by removing the organic solvent from the resin dispersion obtained in Step 2.
Step 4: A step of mixing a surfactant with the aqueous dispersion obtained in Step 3.

  Furthermore, the method for producing an electrophotographic toner of the present invention includes a step of obtaining an aqueous dispersion of a binder resin for toner through the steps 1 to 4 (a step of producing an aqueous dispersion of a binder resin), the aqueous dispersion A process of aggregating resin particles therein to obtain aggregated particles (aggregation process), and a process of fusing (coalescence) the obtained aggregated particles to obtain fused particles (coalescence particles) ) Step) is preferred.

In the present invention, the “aqueous” of the “aqueous dispersion” may contain a solvent such as an organic solvent, but water is preferably 50% by weight or more, preferably 70% by weight or more, more preferably 90%. It contains at least 99% by weight, more preferably at least 99% by weight.
When mixing / dispersing the binder resin, organic solvent, surfactant, neutralizing agent, and water, use chemical dispersion methods such as phase inversion emulsification methods and mechanical dispersion methods such as homogenizers and ultrasonic dispersers. Can do.

[Process for producing aqueous dispersion of binder resin]
[Step 1]
Step 1 is a step of obtaining a mixture by mixing at least a binder resin, an organic solvent, and a neutralizing agent. The binder resin used in the present invention includes a crystalline polyester resin. The content of the crystalline polyester resin in the binder resin is preferably 65% by weight or more, more preferably from the viewpoint of improving the dispersion stability and the low-temperature fixability and heat-resistant storage stability of the aqueous dispersion. Is 65 to 100% by weight, more preferably 75 to 100% by weight, still more preferably 85 to 100% by weight, and still more preferably substantially 100% by weight.

(Binder resin)
The binder resin used in the present invention is not particularly limited as long as it is a binder resin for toners having physical properties generally used for toners. However, a condensation polymerization of an alcohol component and a carboxylic acid component is performed. The polyester resin obtained is preferable. Hereinafter, typical embodiments of the polyester resin for toner used in the present invention will be described.
The polyester-based resin used in the present invention includes a crystalline polyester resin and may further include an amorphous resin. Here, the crystallinity of a resin such as polyester is the crystallinity defined by the ratio between the softening point and the maximum endothermic peak temperature by a differential scanning calorimeter (DSC), that is, “softening point / maximum endothermic peak temperature”. Expressed by an index. Generally, when the crystallinity index exceeds 1.4, the resin is amorphous, and when it is less than 0.6, the crystallinity is low and there are many amorphous portions. In the present invention, “crystalline polyester” refers to a polyester having a crystallinity index of 0.6 to 1.4, preferably 0.8 to 1.2, more preferably 0.9 to 1.1. “Amorphous resin” refers to a resin having a crystallinity index greater than 1.4 or less than 0.6.
The above “maximum endothermic peak temperature” refers to the temperature of the peak on the highest temperature side among the endothermic peaks observed under the measurement method conditions described in the examples. If the maximum peak temperature is within 20 ° C. from the softening point, the maximum peak temperature is the melting point of the crystalline resin (crystalline polyester), and the peak with the difference from the softening point exceeding 20 ° C. is glass of amorphous resin. The peak is attributed to the transition.
In the present invention, the crystallinity of the polyester-based resin can be adjusted by the type and ratio of raw material monomers, production conditions (for example, reaction temperature, reaction time, cooling rate) and the like.

<Crystalline polyester resin>
The crystalline polyester resin can be produced by polycondensation reaction between an acid component and an alcohol component. A catalyst can be preferably used in the polycondensation reaction.

Examples of the acid component include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, and trivalent or higher polyvalent carboxylic acids. Among them, improvement of toner low-temperature fixability, charging stability under high temperature and high humidity From the viewpoint of improving the stability and heat-resistant storage stability, aliphatic dicarboxylic acids are preferred.
The acid component includes not only a free acid but also an anhydride that decomposes during the reaction to produce an acid, and an alkyl ester having 1 to 3 carbon atoms.
The aliphatic dicarboxylic acid preferably has 2 to 18 carbon atoms, and more preferably 8 to 12 carbon atoms, from the viewpoints of improving low-temperature fixability of the toner, improving charging stability under high temperature and high humidity, and improving heat-resistant storage stability.
Examples of the aliphatic carboxylic acid having 2 to 18 carbon atoms include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, 1,12-dodecanedioic acid. , Azelaic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid, etc. Among them, from the viewpoint of improving low-temperature fixability of toner, improving charging stability under high temperature and high humidity, and improving heat storage stability, sebacic acid is preferable.
Examples of the alicyclic dicarboxylic acid include cyclohexane dicarboxylic acid.
Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid and the like.
Examples of the trivalent or higher polyvalent carboxylic acid include trimellitic acid and pyromellitic acid.
These can be used alone or in combination of two or more.

Examples of alcohol components include aliphatic diols, aromatic diols, hydrogenated bisphenol A, and trihydric or higher polyhydric alcohols, among others, promoting the crystallization of polyester and improving the low-temperature fixability of the toner. From the viewpoint of making them, an aliphatic diol is preferable.
Among the aliphatic diols, α, ω-alkanediol is preferable from the viewpoint of promoting the crystallization of polyester and improving the low-temperature fixability of the toner.
The α, ω-alkanediol preferably has 2 to 18 carbon atoms, more preferably 4 to 12 carbon atoms, and still more preferably 6 to 12 carbon atoms from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the obtained toner. .
Examples of the α, ω-alkanediol having 2 to 18 carbon atoms include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, Examples include 7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and the like. From the viewpoint of improving charging stability under moisture and improving heat-resistant storage stability, 1,6-hexanediol and 1,4-butanediol are preferable, and 1,6-hexanediol is more preferable.
The α, ω-alkanediol having 2 to 18 carbon atoms can be used alone or in combination of two or more. When two types are used, a combination of 1,6-hexanediol and 1,4-butanediol is preferable.
Examples of aromatic diols include alkylene (2 to 3 carbon) oxide adducts (average number of added moles 1 to 16) of bisphenol A.
Examples of the trihydric or higher polyhydric alcohol include glycerin and pentaerythritol.

  The alcohol component can be used alone or in combination of two or more. From the viewpoint of promoting the crystallization of polyester, the content of the α, ω-alkanediol having 2 to 18 carbon atoms in the alcohol component is 80-100 mol% is preferable, 90-100 mol% is more preferable, and 100 mol% is still more preferable substantially.

  As a combination of an acid component and an alcohol component, a combination of an aliphatic dicarboxylic acid and an aliphatic diol is preferable from the viewpoint of improving low-temperature fixability of the toner, improving charging stability under high temperature and high humidity, and improving heat-resistant storage stability. A combination of an α, ω-alkanediol having 2 to 18 carbon atoms and an aliphatic dicarboxylic acid having 8 to 12 carbon atoms is more preferable.

（式中、Ｒは、炭素数２又は３のアルキレン基を示す。ｘ及びｙは正の数を示し、ｘとｙの和は１〜１６、好ましくは１．５〜５である。） <Amorphous resin>
The amorphous resin can be produced by polycondensation reaction between an acid component and an alcohol component.
Examples of the alcohol component that is a raw material monomer for an amorphous resin include aliphatic diols, aromatic diols, and trihydric or higher polyhydric alcohols. These alcohol components can be used alone or in combination of two or more.
The alcohol component, which is a raw material monomer of the amorphous resin, preferably contains an alkylene oxide adduct of bisphenol A represented by the following formula (I) from the viewpoint of making the resin amorphous.

(In the formula, R represents an alkylene group having 2 or 3 carbon atoms. X and y represent a positive number, and the sum of x and y is 1 to 16, preferably 1.5 to 5.)

As the alkylene oxide adduct of bisphenol A represented by the above formula (I), specifically, a polyoxypropylene adduct of 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4- Hydroxyphenyl) propane polyoxyethylene adduct and the like.
The content of the alkylene oxide adduct of bisphenol A represented by the formula (I) is selected from the viewpoint of making the polyester resin amorphous and improving the heat-resistant storage stability of the toner. , Preferably it is 70-100 mol%, More preferably, it is 80-100 mol%, More preferably, it is 90-100 mol%.

Examples of the polyhydric alcohol component other than the alkylene oxide adduct of bisphenol A represented by the formula (I) and the aliphatic diol having 2 to 14 carbon atoms that can be used as the alcohol component include, for example, low-temperature fixability of toner, From the viewpoint of improving the heat-resistant storage stability, trivalent or higher alcohols can be mentioned.
Specific examples of the trivalent or higher alcohol include glycerin, pentaerythritol, trimethylolpropane, and the like, and glycerin is preferable from the viewpoint of reactivity and molecular weight adjustment.
The content of the trivalent or higher alcohol is preferably 0.1 to 30 mol%, more preferably 1 to 30 mol% in the alcohol component of the amorphous resin, from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. Preferably, 5 to 30 mol% is more preferable.

Examples of the carboxylic acid component of the amorphous resin include aliphatic dicarboxylic acids, aromatic dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, acid anhydrides thereof, and alkyl (1 to 3 carbon atoms) esters thereof. Can be mentioned. These carboxylic acid components can be used alone or in combination of two or more.
Specific examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,10- A decanedicarboxylic acid is mentioned. Examples of the aliphatic dicarboxylic acid also include succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms such as dodecyl succinic acid, dodecenyl succinic acid, and octenyl succinic acid. Among these, dodecenyl succinic anhydride is preferable from the viewpoint of the wax inclusion property of the toner.
Specific examples of the aromatic dicarboxylic acid include terephthalic acid, phthalic acid, and isophthalic acid. Among these, terephthalic acid is preferable from the viewpoint of improving the heat resistant storage stability of the toner.
Specific examples of the trivalent or higher polyvalent carboxylic acid include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid. An acid (pyromellitic acid) is mentioned. Among these, trimellitic anhydride is preferable from the viewpoint of improving the heat resistant storage stability of the toner.
The content of the trivalent or higher polyvalent carboxylic acid is preferably 0.1 to 30 mol%, more preferably 1 to 30 mol% in the carboxylic acid component of the amorphous resin, from the viewpoint of improving the heat-resistant storage stability of the toner. Preferably, 5-30 mol% is still more preferable, and 5-15 mol% is still more preferable.

  In addition, from the viewpoint of molecular weight adjustment and physical property adjustment, the alcohol component may appropriately contain a monovalent alcohol, and the carboxylic acid component may appropriately contain a monovalent carboxylic acid compound.

<Molar ratio of alcohol component to carboxylic acid component>
The molar ratio of the alcohol component and the carboxylic acid component (carboxylic acid component / alcohol component), which is a raw material monomer for the polycondensation reaction, is preferably 0.50 to 1.50 from the viewpoints of reactivity, molecular weight adjustment, and physical property adjustment. More preferably, it is 0.7-1.3, More preferably, it is 0.85-1.2, More preferably, it is 0.95-1.1.

<Composite resin>
The polyester-based binder resin used in the present invention uses (i) a vinyl-based resin raw material monomer, and (ii) a bi-reactive monomer capable of reacting with both the vinyl-based resin raw material monomer and the alcohol component. By subjecting it to an addition polymerization reaction in addition to a condensation polymerization reaction, it is also possible to make a polyester resin into a composite resin. From the viewpoint of improving low-temperature fixability of toner, improving charging stability under high temperature and high humidity, and improving heat-resistant storage stability Therefore, a composite resin may be used.
Raw material monomers for vinyl resin components include styrene compounds such as styrene and α-methylstyrene; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; halovinyls such as vinyl chloride; vinyl acetate Vinyl esters such as vinyl propionate; alkyl (carbon number 1 to 18) esters of (meth) acrylic acid; esters of ethylenic monocarboxylic acids such as dimethylaminoethyl (meth) acrylate; vinyl ethers such as vinyl methyl ether And vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinylpyrrolidone and the like. From the viewpoint of reactivity, a styrene compound and an alkyl (carbon number 1 to 18) ester of (meth) acrylic acid are preferable, styrene, butyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate are more preferable, and styrene and acrylic The acid 2-ethylhexyl is more preferable, and styrene is still more preferable.
The content of the alkyl ester of styrene and / or (meth) acrylic acid in the vinyl resin component is preferably 50% by weight or more, more preferably 80 to 100% by weight.
The amount of the raw material monomer used for the vinyl resin component is the weight ratio of the polyester component to the vinyl resin component from the viewpoint of improving the low temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat resistant storage stability. The weight of the polyester component / the weight of the vinyl resin component is preferably 50/50 to 95/5, more preferably 65/45 to 90/10, and preferably 70/30 to 85/15.

The bi-reactive monomer capable of reacting with any of the vinyl resin raw material monomer and the alcohol component is selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group, and a secondary amino group in the molecule. Examples thereof include compounds having at least one functional group selected and an ethylenically unsaturated bond. Among these, from the viewpoint of reactivity, a compound having a hydroxyl group and / or a carboxyl group and an ethylenically unsaturated bond is preferable, and a compound having a carboxyl group and an ethylenically unsaturated bond is more preferable. By using such a bireactive monomer, the dispersibility of the vinyl resin component dispersed in the polyester resin component of the composite resin can be further improved.
Examples of the both reactive monomers include acrylic acid, methacrylic acid, maleic acid and maleic anhydride from the viewpoint of the reactivity of the condensation polymerization reaction and the addition polymerization reaction. Acrylic acid and methacrylic acid are more preferred.
The amount of both reactive monomers used is the dispersibility of the vinyl resin component dispersed in the polyester resin component of the composite resin, the low temperature fixability of the toner, the charging stability under high temperature and high humidity, and the heat resistant storage stability. From the viewpoint, 2 to 25 mol% is preferable, 3 to 20 mol% is more preferable, 5 to 15 mol% is further preferable, and 6 to 10 mol% is still more preferable with respect to 100 mol% of the alcohol component.
From the same viewpoint, 2 to 25% by weight is preferable, 3 to 20% by weight is more preferable, 4 to 15% by weight is further preferable, and 5 to 10% by weight is preferable with respect to 100% by weight of the raw material monomer of the vinyl resin component. Weight percent is even more preferred.

<Physical properties of binder resin>
The softening point of the binder resin used in the present invention is preferably 60 to 160 ° C, more preferably 60 to 140 ° C, and still more preferably 65 to 130 ° C, from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. 65 to 120 ° C. is more preferable, and 70 to 110 ° C. is still more preferable.
Further, the glass transition temperature of the binder resin of the present invention is preferably 45 to 85 ° C., more preferably 50 to 80 ° C. from the viewpoint of improving the low temperature fixability and heat resistant storage stability of the toner. The glass transition temperature is a physical property peculiar to an amorphous resin, and is distinguished from the maximum peak temperature of heat of fusion.

  The number average molecular weight of the binder resin is preferably from 1,000 to 6,000, and more preferably from 2,000 to 5,000, from the viewpoint of improving the low temperature fixability and heat resistant storage stability of the toner. The weight average molecular weight is preferably 6,000 to 1,000,000, more preferably 8,000 to 1,000,000, and still more preferably, from the viewpoint of improving the low temperature fixability and heat resistant storage stability of the toner. 10,000 to 500,000. The number average molecular weight and the weight average molecular weight are both values obtained by measuring the tetrahydrofuran-soluble content.

The acid value of the binder resin is preferably from 1 to 50 mgKOH / g, more preferably from 2 to 45 mgKOH / g, from the viewpoint of improving the low-temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat-resistant storage stability. 5 to 40 mgKOH / g is more preferable, 10 to 35 mgKOH / g is more preferable, and 15 to 35 mgKOH / g is more preferable.
The hydroxyl value of the polyester resin is preferably 1 to 70 mgKOH / g, more preferably 2 to 60 mgKOH / g, and still more preferably 3 to 50 mgKOH / g from the same viewpoint as described above.
The softening point, glass transition temperature, number average molecular weight, weight average molecular weight, acid value and hydroxyl value can be appropriately adjusted by adjusting the raw material monomer composition, molecular weight, catalyst amount, etc., or by selecting reaction conditions.

<Production method of polyester resin>
The polyester resin is obtained by a condensation polymerization reaction between an alcohol component and a carboxylic acid component. The polycondensation reaction is preferably performed in the presence of an esterification catalyst, and is more preferably performed in the presence of an esterification catalyst and a pyrogallol compound from the viewpoints of reactivity, molecular weight adjustment, and resin physical property adjustment.

<Esterification catalyst>
Examples of the esterification catalyst suitably used for the condensation polymerization include a titanium compound and a tin (II) compound having no Sn-C bond, and these may be used alone or in combination of two or more. it can.

  As a titanium compound, the titanium compound which has a Ti-O bond is preferable, and the compound which has a C1-28 total carbon number alkoxy group, an alkenyloxy group, or an acyloxy group is more preferable.

  Examples of the tin (II) compound having no Sn—C bond include a tin (II) compound having a Sn—O bond, a tin (II) compound having a Sn—X (X represents a halogen atom) bond, and the like. Preferred is a tin (II) compound having a Sn-O bond, and among them, di (2-ethylhexanoic acid) tin (II) is more preferable from the viewpoints of reactivity, molecular weight adjustment, and resin physical property adjustment. .

  The amount of the esterification catalyst is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component, from the viewpoints of reactivity, molecular weight adjustment, and resin physical property adjustment. More preferably, it is 1 to 0.6 parts by weight.

<Pyrogallol compound>
A pyrogallol compound has a benzene ring in which three hydrogen atoms adjacent to each other are substituted with a hydroxyl group, and pyrogallol, gallic acid, gallic acid ester, 2,3,4-trihydroxybenzophenone, 2,2 ′, Examples include benzophenone derivatives such as 3,4-tetrahydroxybenzophenone, catechin derivatives such as epigallocatechin and epigallocatechin gallate, and gallic acid is preferred from the viewpoint of reactivity.
The abundance of the pyrogallol compound in the condensation polymerization reaction is preferably 0.001 to 1 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component subjected to the condensation polymerization reaction, from the viewpoint of reactivity. 0.005-0.4 weight part is more preferable, 0.01-0.2 weight part is still more preferable, 0.01-0.1 weight part is still more preferable. Here, the abundance of the pyrogallol compound means the total amount of the pyrogallol compound subjected to the condensation polymerization reaction.
From the viewpoint of reactivity, the weight ratio of the pyrogallol compound to the esterification catalyst (pyrogallol compound / esterification catalyst) is preferably 0.01 to 0.5, more preferably 0.02 to 0.3, and 0.03. -0.2 is still more preferable, and 0.03-0.1 is still more preferable.

The condensation polymerization reaction between the alcohol component and the carboxylic acid component can be performed, for example, in the presence of the esterification catalyst in an inert gas atmosphere at a temperature of 120 to 250 ° C. From the viewpoint of reactivity, 140 ˜245 ° C. is preferred.
In addition, for example, all monomers are charged together to increase the strength of the resin, or divalent monomers are first reacted to reduce low molecular weight components, and then trivalent or higher monomers are added and reacted. A method may be used. Further, the reaction may be accelerated by reducing the pressure of the reaction system in the latter half of the polymerization.

<Production method of composite resin>
The composite resin is preferably produced by any of the following methods (1) to (3). In addition, it is preferable that both reactive monomers are supplied to a reaction system with the raw material monomer of a vinyl-type resin component from a reactive viewpoint.
(1) A method of performing a step (B) of an addition polymerization reaction using a raw material monomer of a vinyl-based resin component and an amphoteric monomer after the step (A) of a condensation polymerization reaction using an alcohol component and a carboxylic acid component.
After the step (B), the reaction temperature is raised again, and if necessary, a tri- or higher-valent raw material monomer of the condensation polymerization resin component is added to the polymerization system as a crosslinking agent, and the condensation polymerization reaction in the step (A). And the reaction with both reactive monomers can be further advanced.

(2) A method in which the step (A) of the condensation polymerization reaction using the raw material monomer of the condensation polymerization resin component is performed after the step (B) of the addition polymerization reaction using the raw material monomer of the vinyl resin component and the both reactive monomers.
The alcohol component and the carboxylic acid component can be present in the reaction system during the addition polymerization reaction, and the condensation polymerization reaction can be started by adding an esterification catalyst at a temperature suitable for the condensation polymerization reaction. The polycondensation reaction can also be initiated by adding it later into the reaction system under temperature conditions suitable for the polymerization reaction. In the former case, the molecular weight and molecular weight distribution can be adjusted by adding the esterification catalyst at a temperature suitable for the condensation polymerization reaction.

(3) A method in which the step (A) of the condensation polymerization reaction with the alcohol component and the carboxylic acid component and the step (B) of the addition polymerization reaction with the raw material monomer and the both reactive monomers of the vinyl resin component are performed in parallel.
In this method, step (A) and step (B) are performed under reaction temperature conditions suitable for addition polymerization reaction, the reaction temperature is increased, and under temperature conditions suitable for condensation polymerization reaction, if necessary, It is preferred to add a trivalent or higher valent raw material monomer of the condensation polymerization resin component to the polymerization system as a crosslinking agent, and further perform the condensation polymerization reaction in the step (A). At that time, under a temperature condition suitable for the condensation polymerization reaction, a radical polymerization inhibitor can be added to advance only the condensation polymerization reaction. Both reactive monomers are involved in the condensation polymerization reaction as well as the addition polymerization reaction.
Among these, the method (1) is preferable from the viewpoint that the degree of freedom of the reaction temperature of the condensation polymerization reaction is high.
The temperature suitable for the addition polymerization reaction is preferably 120 ° C. or higher and lower than 180 ° C., more preferably 140 ° C. or higher and lower than 180 ° C., from the viewpoint of reactivity. As described above, the temperature suitable for the condensation polymerization reaction is preferably 120 to 250 ° C, more preferably 140 to 245 ° C, from the viewpoint of reactivity.
The methods (1) to (3) are preferably performed in the same container.

  From the viewpoint of dispersion stability of the binder resin, the content of the binder resin in the mixture obtained in step 1 is preferably 35 to 98% by weight, more preferably 40 to 95% by weight, and further 40 to 90% by weight. Preferably, 50 to 90% by weight is even more preferable, and 70 to 80% by weight is even more preferable.

(Organic solvent)
From the viewpoint of improving the dispersibility of the polyester-based resin, the organic solvent has a solubility parameter (SP value: POLYMER HANDBOOK THIRD EDITION 1989 by John Wiley & Sons, Inc.) of 15.0 to 26.0 MPa ^{1 / 2} is preferable, 16.0 to 24.0 MPa ^1/2 is more preferable, and 17.0 to 22.0 MPa ^1/2 is more preferable.
Specific examples include alcohol solvents such as ethanol (26.0), isopropanol (23.5), and isobutanol (21.5); acetone (20.3), methyl ethyl ketone (19.0), methyl isobutyl ketone. Ketone solvents such as (17.2) and diethyl ketone (18.0); ether solvents such as dibutyl ether (16.5), tetrahydrofuran (18.6) and dioxane (20.5); ethyl acetate (18.6) and acetate solvents such as isopropyl acetate (17.4). The value in parentheses indicates the SP value. Of these, ketone solvents and acetate solvents are preferred from the viewpoints of improving low-temperature fixability of the toner, improving charging stability under high temperature and high humidity and improving heat-resistant storage stability, and methyl ethyl ketone, ethyl acetate and isopropyl acetate are preferred. More preferably, from the viewpoint of heat-resistant storage stability of the toner, ethyl acetate and isopropyl acetate are preferable, and ethyl acetate is more preferable.

The amount of the organic solvent used is preferably 3 to 500 parts by weight with respect to 100 parts by weight of the binder resin from the viewpoint of improving the low-temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat-resistant storage stability. 5 to 150 parts by weight, more preferably 5 to 100 parts by weight, still more preferably 10 to 80 parts by weight, and still more preferably 10 to 40 parts by weight.
The weight ratio of the binder resin to the organic solvent (binder resin / organic solvent) is preferably from the viewpoint of improving the low-temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat resistant storage stability. 1/5 to 1 / 0.03, more preferably 1 / 1.5 to 1 / 0.05, still more preferably 1/1 to 1 / 0.05, still more preferably 1 / 0.8 to 1 / 0.1, more preferably 1 / 0.4 to 1 / 0.1.

(Neutralizer)
Examples of the neutralizing agent used in the present invention include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; ammonia, trimethylamine, ethylamine, diethylamine, triethylamine, triethanolamine, and tributylamine. Of the organic base. Among these, a neutralizing agent having a pKa of 12 or less is preferable from the viewpoint of improving the low-temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat-resistant storage stability, and ammonia (pKa = 9.3). , Triethylamine (pKa = 9.8) is preferable, and ammonia is more preferable.
The degree of neutralization of the polyester-based resin with a neutralizing agent is preferably 20 to 100 mol%, from the viewpoint of improving low-temperature fixability of the toner, improving charging stability under high temperature and high humidity, and improving heat-resistant storage stability. More preferably, mol% is more preferable, 30-80 mol% is still more preferable, 40-70 mol% is still more preferable, and 50-65 mol% is still more preferable. In addition, the neutralization degree (mol%) of resin can be calculated | required by a following formula.
Degree of neutralization = {[weight of neutralizer (g) / equivalent of neutralizer] / [[acid value of resin (KOH mg / g) × resin weight (g)] / (56 × 1000)]} × 100

In step 1, the order of adding the raw materials is not limited, but it is preferable that the neutralizing agent is mixed after the binder resin and the organic solvent are mixed.
At the time of mixing, it is preferable to stir with a commonly used mixing and stirring device such as an anchor blade or an external circulation stirring device.

  The temperature at the time of mixing in Step 1 is preferably 5 to 50 ° C., more preferably 10 to 40 ° C., and still more preferably 20 to 20 ° C. from the viewpoints of stabilizing the process temperature, shortening the process time, and reducing the viscosity of the solution. 35 ° C. Stirring is preferably performed until there is no significant phase separation or insoluble matter, and the stirring time is preferably 0.1 to 5 hours, more preferably depending on the stirring speed and temperature conditions. Is 0.2 to 3 hours, more preferably 0.3 to 1 hour.

  In addition, you may add arbitrary components to the process 1 of this invention in the range which does not affect the effect of this invention. For example, inorganic salts, organic solvents other than those described above, surfactants and the like can be mentioned.

[Step 2]
Step 2 is a step of obtaining a resin dispersion by adding and mixing at least water and a surfactant to the mixture obtained in Step 1.

(Surfactant)
Examples of the surfactant include nonionic surfactants, anionic surfactants, and cationic surfactants. Among these, anionic surfactants are preferable from the viewpoint of dispersibility of the binder resin.

Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl aryl ethers such as polyoxyethylene lauryl ether, polyoxyethylene alkyl ethers, polyethylene glycol monolaurate , Polyoxyethylene fatty acid esters such as polyethylene glycol monostearate and polyethylene glycol monooleate, and oxyethylene / oxypropylene block copolymers. Among these, from the viewpoint of emulsion stability of the resin, polyoxyethylene Alkyl ethers are preferred.
Examples of the anionic surfactant include sulfate ester, sulfonate, phosphate ester, and soap (for example, alkyl ether carboxylate). Specific examples include sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium alkyl ether sulfate, etc. Among these, sodium alkylbenzene sulfonate and sodium alkyl ether sulfate are preferred from the viewpoint of emulsion stability of the resin, and dodecylbenzene sulfone. Sodium acid is more preferred.
Examples of the cationic surfactant include alkyltrimethylammonium chloride and dialkyldimethylammonium chloride.

  The total addition amount of the surfactant is preferably 20 parts by weight or less, more preferably 100 parts by weight or less with respect to 100 parts by weight of the binder resin containing the crystalline polyester resin, from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. 15 parts by weight or less, more preferably 0.1 to 10 parts by weight, still more preferably 0.5 to 5 parts by weight.

The addition amount of the surfactant added in Step 2 and Step 4 is the total addition amount of the surfactant from the viewpoint of improving the low temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat resistant storage stability. 80 to 100% by weight, preferably 85 to 100% by weight, more preferably 90 to 100% by weight, and still more preferably 100% by weight.
Further, the ratio of the weight of the surfactant added in step 2 to the weight of the surfactant added in step 4 is such that the toner has low temperature fixability, charging stability under high temperature and high humidity, and heat resistant storage stability. In view of the above, the weight of the surfactant added in step 2 / the weight of the surfactant added in step 4 is 10/90 to 40/60, preferably 15/85 to 38/62, more preferably 20 / 80 to 35/65, more preferably 25/75 to 35/65.

  The addition amount of the surfactant in the step 2 is preferably 0.01 to 8 weights with respect to 100 parts by weight of the binder resin containing the crystalline polyester resin, from the viewpoint of improving the low temperature fixability and heat resistant storage stability of the toner. Parts, more preferably 0.05 to 6 parts by weight, still more preferably 0.1 to 4 parts by weight, still more preferably 0.5 to 2 parts by weight.

  The amount of water used in step 2 is such that the weight ratio of water to organic solvent (water / organic solvent) is from the viewpoint of improving the low-temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat-resistant storage stability. The ratio is preferably 70/30 to 98/2, more preferably 80/20 to 98/2, and still more preferably 85/15 to 95/5.

  The amount of water used in step 2 is the weight ratio of water to binder resin (water / condensation) from the viewpoints of improving the low temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat resistant storage stability. Is preferably 20/80 to 95/5, more preferably 20/80 to 92/8, still more preferably 40/60 to 91/9 (outside of actual 11), and still more preferably 45/55. 91/9, more preferably 45/55 to 85/15 (outside actual 10), still more preferably 50/50 to 80/20 (outside actual 9, 12), still more preferably 60/40 to 75 / 25.

At the time of mixing, it is preferable to stir with a commonly used mixing and stirring device such as an anchor blade or an external circulation stirring device.
When a mixing and stirring device such as an anchor blade is used, the peripheral speed of stirring is preferably 200 to 20 m / min, more preferably 150 to 40 m / min, and further preferably 100 to 60 m / min from the viewpoint of dispersibility.

  The temperature at the time of mixing in step 2 is preferably 5 to 50 ° C., more preferably 10 to 40 ° C., and still more preferably 20 to 20 ° C. from the viewpoints of stabilizing the process temperature, shortening the process time, and reducing the viscosity of the solution. 35 ° C.

  In step 2, the method for adding and mixing water and surfactant is not particularly limited, and the total amount may be added to the mixture obtained in step 1 at once, or divided into several times or added dropwise. It may be added intermittently or continuously through a pump or the like. From the viewpoint of the dispersibility of the mixture obtained in step 1, it is preferable to intermittently or continuously add a surfactant aqueous solution in which a surfactant is previously dissolved in water. The addition time is preferably 0.5 to 5 hours, more preferably 1 to 3 hours, although it depends on the stirring speed and temperature conditions from the viewpoint of dispersibility of the mixture obtained in Step 1.

[Step 3]
Step 3 is a step of obtaining an aqueous dispersion of the binder resin by removing the organic solvent from the resin dispersion obtained in Step 2.

  The method for removing the organic solvent in Step 3 is not particularly limited, and any method can be used. However, since it is dissolved in water, it is preferably distilled. In addition, the organic solvent may not be completely removed and may remain in the aqueous dispersion. In this case, the residual amount of the organic solvent in the aqueous dispersion is preferably 1% by weight or less, more preferably 0.5% by weight or less, further preferably 0.1% by weight or less, and substantially 0% even more. preferable.

  When removing the organic solvent by distillation, it is preferable to raise the temperature to a temperature equal to or higher than the boiling point of the organic solvent to be used while stirring. Further, from the viewpoint of maintaining the dispersion stability of the binder resin, it is more preferable to evaporate by raising the temperature to a temperature equal to or higher than the boiling point of the organic solvent to be used at that pressure. Note that the temperature may be increased after the pressure is reduced, or the pressure may be decreased after the temperature is increased. From the viewpoint of maintaining the dispersion stability of the binder resin, it is preferable to distill off at a constant temperature and pressure.

[Step 4]
Step 4 is a step of mixing a surfactant with the aqueous dispersion obtained in Step 3.

(Surfactant)
Examples of the surfactant include nonionic surfactants, anionic surfactants, and cationic surfactants. Among these, anionic surfactants are preferable from the viewpoint of dispersibility of the binder resin.

Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl aryl ethers such as polyoxyethylene lauryl ether, polyoxyethylene alkyl ethers, polyethylene glycol monolaurate , Polyoxyethylene fatty acid esters such as polyethylene glycol monostearate and polyethylene glycol monooleate, and oxyethylene / oxypropylene block copolymers. Among these, from the viewpoint of emulsion stability of the resin, polyoxyethylene Alkyl ethers are preferred.
Examples of the anionic surfactant include sulfate ester, sulfonate, phosphate ester, and soap (for example, alkyl ether carboxylate). Specific examples include sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium alkyl ether sulfate, etc. Among these, sodium alkylbenzene sulfonate and sodium alkyl ether sulfate are preferred from the viewpoint of emulsion stability of the resin, and dodecylbenzene sulfone. Sodium acid is more preferred.
Examples of the cationic surfactant include alkyltrimethylammonium chloride and dialkyldimethylammonium chloride.

  The surfactant used in step 4 may be the same as or different from the surfactant used in step 2, but is the same from the viewpoint of the dispersibility of the binder resin and the cohesiveness in the subsequent aggregation step. It is preferable that

  The addition amount of the surfactant in the step 4 is preferably 0.015 to 12 weights with respect to 100 parts by weight of the binder resin containing the crystalline polyester resin from the viewpoint of improving the low temperature fixability and heat resistant storage stability of the toner. Parts, more preferably 0.075 to 9 parts by weight or less, still more preferably 0.15 to 6 parts by weight, still more preferably 0.75 to 3 parts by weight.

When the surfactant is added, it is preferable to stir with a commonly used mixing and stirring device such as an anchor blade or an external circulation stirring device.
When a mixing and stirring device such as an anchor blade is used, the peripheral speed of stirring is preferably 200 to 20 m / min, more preferably 150 to 40 m / min, and further preferably 100 to 60 m / min from the viewpoint of dispersibility.

  The temperature during addition of the surfactant in step 4 is preferably 5 to 50 ° C, more preferably 10 to 40 ° C, and still more preferably 20 to 35 ° C, from the viewpoint of dispersibility of the surfactant in water. .

  The solid content concentration of the aqueous dispersion obtained through the production process of the aqueous dispersion including Step 1 to Step 4 is preferably 3 by appropriately adding water from the viewpoint of the stability of the dispersion and ease of handling. It is adjusted to -40% by weight, more preferably 5-30% by weight, still more preferably 15-25% by weight. In addition, solid content is the total amount of non-volatile components, such as resin and surfactant.

  From the viewpoint of improving the low-temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat resistant storage stability, preferably after step 3, preferably after step 4, the pH of the aqueous dispersion is 3 or less, preferably Is preferably adjusted to 1 to 3, more preferably 1.5 to 2.5. Moreover, it is preferable to adjust pH of an aqueous dispersion to 4 or more after that, Preferably it is 4-6, More preferably, it is 4.5-5.5.

[Aggregation process]
In the aggregation step, it is preferable that the resin particles in the aqueous dispersion of the binder resin for toner are aggregated to obtain a dispersion of aggregated particles.

In the aggregation process, it is preferable to add an aggregating agent in order to efficiently perform aggregation. As the flocculant, a quaternary salt cationic surfactant, an organic flocculant such as polyethyleneimine; and an inorganic flocculant such as inorganic metal salt and inorganic ammonium salt are used. From the viewpoints of improving the low-temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat-resistant storage stability, an inorganic flocculant is preferable, and an inorganic metal salt is particularly preferable.
Examples of the inorganic metal salt include sodium sulfate, sodium chloride, calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, and aluminum chloride. The valence of the central metal of the inorganic metal salt is preferably 2 or more from the viewpoint of improving the low temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat resistant storage stability.
In the case of adding a flocculant, the amount added is from about 0.1 parts by weight with respect to 100 parts by weight of the binder resin from the viewpoint of improving low-temperature fixability of the toner, improving charging stability under high temperature and high humidity, and improving heat-resistant storage stability. 001-10 parts by weight is preferred, 0.005-7 parts by weight is more preferred, 0.005-5 parts by weight is still more preferred, and 0.01-1 part by weight is even more preferred.

The flocculant is preferably added after being dissolved in an aqueous medium, and it is preferable that the flocculant is sufficiently stirred at the time of addition of the flocculant and after the addition.
In the aggregation step, the solid content concentration in the system is preferably 5 to 50% by weight, more preferably 5 to 40% by weight, and still more preferably 5 to 30% by weight in order to cause uniform aggregation.
In the aggregating step, from the viewpoint of uniformly dispersing the aggregating agent and causing uniform agglomeration, it is preferable to add the aggregating agent at 20 to 40 ° C. It is preferable to hold | maintain at 40-60 degreeC until it becomes.

  When the aqueous dispersion in the present invention is agglomerated in the aggregating step, the aqueous dispersion using a binder resin mainly composed of an amorphous polyester resin is coagulated in the range that does not impair the effects of the present invention. Also good. The content of the aqueous dispersion using a binder resin mainly composed of an amorphous polyester resin is from the viewpoint of improving the low temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat resistant storage stability. In addition, 0 to 75 parts by weight is preferable, 0 to 70 parts by weight is further preferable, 10 to 70 parts by weight is further preferable, and 20 to 40 parts by weight is the most with respect to 100% by weight of the total aqueous dispersion of the binder resin. preferable.

  In the aggregating step, a coloring agent, a charge control agent, a release agent, a conductivity adjusting agent, a reinforcing filler such as a fibrous substance, an antioxidant, and an anti-aging agent may be added before aggregation. Good. The additive can also be used as an aqueous dispersion.

  There is no restriction | limiting in particular as a coloring agent, A well-known coloring agent is mentioned, According to the objective, it can select suitably. Specifically, carbon black, inorganic composite oxide, chrome yellow, hansa yellow, benzidine yellow, selenium yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, etc. Various pigments: acridine, xanthene, azo, benzoquinone, azine, anthraquinone, indico, Indigo dyes, phthalocyanine, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, thiazine, and include various dyes of thiazole, and the like. These can be used alone or in combination of two or more. The amount of the colorant added is preferably 0.1 to 20 parts by weight and more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin from the viewpoint of improving the image quality.

  Examples of charge control agents include chromium azo dyes, iron azo dyes, aluminum azo dyes, and salicylic acid metal complexes. Various charge control agents may be used alone or in combination of two or more. When the charge control agent is added, the addition amount is preferably 0.1 to 8 parts by weight and more preferably 0.3 to 7 parts by weight with respect to 100 parts by weight of the binder resin from the viewpoint of improving the image quality. .

Release agents include fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide; plant waxes such as carnauba wax, rice wax, candelilla wax, wood wax, and jojoba oil; Animal waxes such as beeswax; waxes such as mineral and petroleum waxes such as montan wax, ozokerite, ceresin, microcrystalline wax, and Fischer-Tropsch wax; polyolefin waxes, paraffin waxes and silicones. You may use a mold release agent individually by 1 type or in combination of 2 or more types. The melting point of the release agent is preferably from 60 to 140 ° C., more preferably from 60 to 100 ° C., from the viewpoints of improving the low temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat resistant storage stability.
When a release agent is added, the addition amount is preferably 1 to 20 parts by weight in the toner from the viewpoint of improving the low-temperature fixability of the toner, improving the charging stability under high temperature and high humidity, and improving the heat-resistant storage stability. 1.5-10 weight part is more preferable, 2-8 weight part is still more preferable, and 2.5-6 weight part is still more preferable.

In addition, additives such as a colorant and a charge control agent may be premixed in the binder resin when preparing the resin particles, or a dispersion in which each additive is separately dispersed in a dispersion medium such as water. It may be prepared, mixed with an aqueous dispersion of a binder resin, and subjected to an aggregation step.
When the additive is previously mixed with the binder resin when preparing the resin particles, it is preferable to melt-knead the binder resin and the additive in advance.
For melt kneading, it is preferable to use an open roll type biaxial kneader. An open roll type biaxial kneader is a kneader in which two rolls are arranged close to each other in parallel, and a heating function or a cooling function can be imparted by passing a heat medium through each roll. Therefore, the open-roll type twin-screw kneader is an open-type part to be melt-kneaded, and is provided with a heating roll and a cooling roll, so that it occurs during melt-kneading unlike a normal twin-screw extruder. The kneading heat can be easily dissipated.
In addition, an aqueous dispersion of each additive can be obtained by mixing each additive, a surfactant, and water and dispersing the mixture with a disperser.

[Fusion (unification) process]
In the fusing (unifying) step, an aggregation stopper is added to the aqueous dispersion of the agglomerated particles obtained in the aggregating step as necessary, and then heated as necessary to fuse the agglomerated particles. 1) to obtain fused particles (unified particles).
The temperature in the system in the fusing (unification) process is the target toner particle size, particle size distribution, shape control and particle fusing properties, improved low-temperature fixability of the toner, and charging under high temperature and high humidity. From the viewpoint of improving stability and heat-resistant storage stability, the softening point of the binder resin is preferably −40 ° C. to + 40 ° C., more preferably −35 ° C. to + 20 ° C., and further preferably −25 ° C. to + 10 ° C. Specifically, it is preferably 70 to 100 ° C, more preferably 70 to 90 ° C. The stirring speed is preferably a speed at which the aggregated particles do not settle.
In addition, when using an aggregation terminator, it is preferable to use a surfactant as the aggregation terminator, and it is more preferable to use an anionic surfactant. Of the anionic surfactants, it is more preferable to use at least one selected from the group consisting of alkyl ether sulfates, alkyl sulfates, and linear alkylbenzene sulfonates, and it is more preferable to use alkyl ether sulfates. .

[Electrophotographic toner]
Electrofused toner (simply referred to as toner) is obtained by subjecting the fused particles (unified particles) obtained in the fusion (unification) step to a solid-liquid separation step such as filtration, a washing step, and a drying step as appropriate. Sometimes).
In the washing step, it is preferable to use an acid in order to remove metal ions on the surface of the toner in order to ensure sufficient charging characteristics and reliability as the toner. Further, it is preferable to completely remove the added nonionic surfactant by washing, and washing with an aqueous solution below the cloud point of the nonionic surfactant is preferred. The washing is preferably performed a plurality of times.
In the drying step, any method such as a vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like can be employed. The water content after drying of the toner is preferably adjusted to 1.5% by weight or less, more preferably 1.0% by weight or less, from the viewpoint of chargeability.

In the electrophotographic toner obtained by the method of the present invention, the toner particles can be used as the toner as they are, but toners obtained by adding an additive (external additive) such as a fluidizing agent to the toner particle surfaces are used as the toner. It is preferable to use it. Examples of the external additive include hydrophobic silica, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, inorganic fine particles such as carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Silica is preferred.
When the surface treatment of toner particles is performed using an external additive, the amount of the external additive added is based on 100 parts by weight of the toner particles before the treatment with the external additive from the viewpoint of improving the storage stability of the toner. Preferably it is 1-5 weight part, More preferably, it is 1-3.5 weight part, More preferably, it is 1-3 weight part.
The volume median particle size (D ₅₀ ) of the toner is preferably 1 to 10 μm, more preferably 2 to 8 μm, still more preferably 3 to 7 μm, and still more preferably 4 to 4 from the viewpoint of improving image quality and productivity. 6 μm.
The CV value of the toner is preferably 45% or less, more preferably 40% or less, still more preferably 35% or less, still more preferably 30% or less, and even more preferably 25%, from the viewpoint of improving image quality and productivity. It is as follows. The CV value can be calculated by the following formula.
CV value (%) = (standard deviation of particle size distribution / volume median particle size (D ₅₀ )) × 100
The electrophotographic toner obtained by the method of the present invention can be used as a one-component developer or as a two-component developer mixed with a carrier.

<Measurement of resin properties>
(Polyester softening point, endothermic maximum peak temperature, melting point and glass transition point)
(1) Softening point Using a flow tester (manufactured by Shimadzu Corporation, trade name: “CFT-500D”), while heating a 1 g sample at a heating rate of 6 ° C./min, A load was applied and extruded from a nozzle having a diameter of 1 mm and a length of 1 mm. The amount of plunger drop of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point.
(2) Endothermic maximum peak temperature, melting point and glass transition point Using a differential scanning calorimeter (manufactured by PerkinElmer, trade name: Pyris 6 DSC), the temperature is raised to 200 ° C., and the temperature lowering rate is 50 ° C./min. The sample cooled to 0 ° C. was measured at a heating rate of 10 ° C./min. Of the endothermic peaks observed, the peak temperature having the maximum peak area was defined as the maximum endothermic peak temperature. In the case of crystalline polyester, the peak temperature was taken as the melting point. In the case of an amorphous polyester, when an endothermic peak is observed, the temperature of the peak is measured, and when a step is observed without a peak being observed, the tangent indicating the maximum slope of the curve of the step and the step The glass transition point was defined as the temperature at the intersection with the base line extension line on the high temperature side.

(Resin acid value)
The acid value of the resin was measured based on the method of JIS K 0070. However, only the measurement solvent was changed from a mixed solvent of ethanol and ether specified in JIS K 0070 to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

<Measurement of physical properties of resin dispersion>
(Volume-median particle size (D ₅₀ ) of resin particles, colorant fine particles, release agent fine particles, charge control agent fine particles and aggregated particles in each dispersion)
What diluted the resin dispersion with ion exchange water so that it might become a solid content concentration of 0.01% by weight is a dynamic light scattering type particle size measuring machine (product name: “ZETASIZER NANO ZS” manufactured by Malvern). The volume-median particle size (D ₅₀ ) was measured under the following conditions.
Measurement temperature: 25 ° C
Medium: Water Measurement cell: Glass Cuvette
Laser specification: He-Ne, 4mW, 633nm
Detection optical system: NIBS, 173 ° C.
Number of measurements: 10 times Isothermal time: 5 minutes Analysis software: Zeta Sizer Software 6.2
Analysis method: General Purpose Mode (cumulant method)

(Measurement of solid content of resin dispersion)
Using an infrared moisture meter (trade name: FD-230, manufactured by Ketto Scientific Laboratory Co., Ltd.), 5 g of the resin dispersion was dried at 150 ° C., measurement mode 96 (monitoring time 2.5 minutes / variation range 0.05). %), And the moisture content (% by weight) of the resin dispersion was measured. The solid content was calculated according to the following formula.
Solid content concentration (% by weight) = 100-M
M: Water content (% by weight) of the resin dispersion = [(W−W0) / W] × 100
W: Sample weight before measurement (initial sample weight)
W0: Sample weight after measurement (absolute dry weight)

(Emulsion pH)
It measured at 20 degreeC using the pH measuring device (The product name: "HM-20P" by Toa DKK Corporation).

<Toner evaluation>
(Minimum toner fixing temperature)
Toner was mounted on a copying machine (trade name: “LaserJet 4200” manufactured by Hewlett-Packard Company), and the toner adhesion amount was adjusted to 0.7 mg / cm ² to obtain an unfixed image. Thereafter, the fixing machine of the copying machine (manufactured by Sharp Corporation, trade name: “AR-505”) was adjusted to a total fixing pressure of 40 kgf and a fixing speed of 390 mm / sec. The fixing test of the unfixed image was performed at each temperature while the temperature was gradually increased from 100 ° C. to 240 ° C. by 10 ° C. A cellophane adhesive tape (manufactured by Mitsubishi Pencil Co., Ltd., trade name: “UNICEF cellophane”, width: 18 mm, JIS Z1522) was attached to the fixed image, passed through a fixing roller set at 30 ° C., and then the tape was peeled off. . The optical reflection density before and after the tape was peeled was measured using a reflection densitometer (product name: “RD-915” manufactured by Gretag Macbeth Co., Ltd.), and the ratio between the two (after peeling / before sticking × 100) was First, the temperature of the fixing roller exceeding 90% was set as the minimum fixing temperature. The lower the minimum fixing temperature, the better the low temperature fixing property.

(Charge stability of toner at high temperature and high humidity (HH))
In a high temperature and high humidity environment with a temperature of 35 ° C. and a relative humidity of 80%, 0.6 g of toner and 19.4 g of silicone ferrite carrier (manufactured by Kanto Denka Kogyo Co., Ltd., average particle size 90 μm) are made of 50 ml cylindrical polypropylene. It put into the bottle, it mixed at 300 r / min using the ball mill, and the charge amount was measured using the Q / M meter (made by EPPING). After a predetermined mixing time, a specified amount of developer is put into a cell attached to the Q / M meter under normal conditions, and only the toner is passed through a sieve having a mesh size of 32 μm (stainless steel, twill, wire diameter: 0.0035 mm). Suctioned for 2 seconds. The change in voltage on the carrier generated at that time was monitored, and the value of [total amount of electricity after 90 seconds (μC) / amount of attracted toner (g)] was defined as the charge amount (μC / g). The ratio between the charge amount after 60 seconds of mixing time and the charge amount after 600 seconds of mixing time (charge amount after 60 seconds of mixing time / charge amount after 600 seconds of mixing time) was calculated. The closer the ratio of both is to 1, the better the charging stability.

(Heat resistant storage stability of toner)
4 g of toner was put in a 20 mL container (diameter: about 3 cm) and left for 24 hours in an environment of temperature 55 ° C. and humidity 65%. After standing, the degree of occurrence of toner aggregation was visually observed, and storage stability was evaluated according to the following evaluation criteria. An evaluation point C or higher is preferable.
A: No aggregation is observed even after 24 hours.
B: Agglomeration is not observed after 12 hours, but after 24 hours, no agglomeration with which the shape of the container can be confirmed when removed from the container is observed, but irregular agglomeration of about 1 cm ³ or less is observed.
C: Aggregation is not observed after 12 hours, but after 24 hours, agglomeration in which the container shape can be confirmed when removed from the container is clearly recognized.
D: Aggregation is observed within 12 hours.

<Manufacture of binder resin>
Production Example 1
(Crystalline polyester resin A)
The polyester raw material monomer, pyrogallol compound and esterification catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser and a nitrogen inlet tube, and the mantle was placed in a nitrogen atmosphere. After heating up to 180 ° C. in the heater, the temperature was raised to 210 ° C. over 10 hours. Then, it reacted until the softening point reached 73.2 degreeC and the crystalline polyester resin A was obtained.

Production Example 2
(Crystalline polyester resin B)
The raw material monomer of polyester other than trimellitic anhydride shown in Table 1, pyrogallol compound and esterification catalyst are put into a 10 liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser and a nitrogen inlet tube. After heating up to 180 ° C. in a mantle heater in a nitrogen atmosphere, the temperature was raised to 210 ° C. over 10 hours. Further, after reacting under reduced pressure of 8 kPa for 1 hour, trimellitic anhydride was added, and the reaction was performed at 210 ° C. until the softening point reached 108 ° C. to obtain crystalline polyester resin B.

Production Example 3
(Crystalline polyester resin C)
A 10-liter four-necked flask equipped with a polyester raw material monomer, a pyrogallol compound, an esterification catalyst, and 5 g of 4-t-butylcatechol shown in Table 1 and equipped with a thermometer, a stainless stir bar, a flow-down condenser, and a nitrogen inlet tube The mixture was heated to 180 ° C. in a mantle heater in a nitrogen atmosphere, and then heated to 210 ° C. over 10 hours. Then, it reacted until the softening point reached 73.2 degreeC and the crystalline polyester resin C was obtained.

Production Example 4
(Crystalline polyester resin D)
The polyester raw material monomer, pyrogallol compound and esterification catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser and a nitrogen inlet tube, and the mantle was placed in a nitrogen atmosphere. After heating up to 180 ° C. in the heater, the temperature was raised to 210 ° C. over 10 hours. Thereafter, it was confirmed that the reaction rate reached 95% or more at 210 ° C., cooled to 160 ° C., and a mixed solution of the vinyl-based resin raw material monomer, the bireactive monomer and the polymerization initiator shown in Table 1 was 1 It was added dropwise over time. Then, after maintaining at 160 degreeC for 30 minutes, it heated up to 210 degreeC, and it reacted until the softening point reached 71.5 degreeC, and obtained the crystalline polyester resin D.

Production Example 5
(Amorphous resin E)
The raw material monomer of polyester other than trimellitic anhydride shown in Table 1, pyrogallol compound and esterification catalyst are put into a 10 liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser and a nitrogen inlet tube. The reaction was performed at 235 ° C. for 10 hours in a mantle heater in a nitrogen atmosphere. Further, after reacting under reduced pressure of 8 kPa for 1 hour, trimellitic anhydride is added, the temperature is raised to 210 ° C., and then the reaction is conducted until the softening point reaches 96.4 ° C. to obtain amorphous resin E. It was.

<Preparation of dispersion other than resin dispersion>
(Preparation of colorant dispersion)
50 g of copper phthalocyanine (manufactured by Dainichi Seika Kogyo Co., Ltd., model number: “ECB-301”), 5 g of nonionic surfactant (polyoxyethylene lauryl ether, product of Kao Corporation, trade name: “Emulgen 150”) And 200 g of ion-exchanged water were mixed and dispersed for 10 minutes using a homogenizer to obtain a colorant dispersion containing colorant fine particles. The volume median particle size (D ₅₀ ) was 120 nm.

(Preparation of release agent dispersion)
Paraffin wax (Nippon Seiwa Co., Ltd., trade name: “HNP9”, melting point: 85 ° C.) 50 g, cationic surfactant (alkylbenzyldimethylammonium chloride, Kao Corporation, trade name: “Sanisol B50”) ) 5 g and 200 g of ion-exchanged water were heated to 95 ° C., and the paraffin wax was dispersed using a homogenizer, and then dispersed with a pressure discharge type homogenizer to obtain a release agent dispersion containing release agent fine particles. Obtained. The volume median particle size (D ₅₀ ) of the paraffin wax was 550 nm.

(Preparation of charge control agent dispersion)
50 g of charge control agent (Orient Chemical Industries, trade name: “Bontron E-84”), 5 g of nonionic surfactant (trade name: “Emulgen 150”, trade name: “Emulgen 150”) and ion-exchanged water 200 g was mixed, glass beads were used, and the mixture was dispersed for 10 minutes using a sand grinder to obtain a charge control agent dispersion liquid containing charge control agent fine particles. The volume median particle size (D ₅₀ ) of the charge control agent was 500 nm.

Example 1
(Production of aqueous dispersion of crystalline polyester resin)
In a 3 L container equipped with a stirrer, reflux condenser, dropping funnel, thermometer and nitrogen inlet tube, 30 g of ethyl acetate and 100 g of crystalline polyester resin A were charged and dissolved at 30 ° C. over 2 hours. A 20 wt% aqueous ammonia solution was added to the obtained solution so that the neutralization degree was 60 mol%, and the mixture was stirred for 30 minutes (step 1). While stirring at 250 r / min (peripheral speed 80 m / min), anionic surfactant (sodium dodecylbenzenesulfonate, manufactured by Kao Corporation, trade name: “Neopelex G-15”) was added to 270 g of ion-exchanged water. Was added over 70 minutes (step 2). Subsequently, after heating up to 50 degreeC over 30 minutes, ethyl acetate was distilled off under reduced pressure (process 3). After cooling to 30 ° C., the solid content concentration of the dispersion was measured and adjusted with ion-exchanged water so as to be 20% by weight to obtain an aqueous dispersion. Thereafter, while stirring at 250 r / min (peripheral speed 80 m / min), an anionic surfactant (trade name: “Neopelex G-15” manufactured by Kao Corporation) was used as a solid content in the aqueous dispersion. 2.1 g was mixed and stirring was continued for 30 minutes (step 4). Thereafter, a 1N aqueous hydrochloric acid solution was added dropwise to adjust the pH to 2, and the mixture was stirred for 1 hour under the condition of 250 r / min (peripheral speed 80 m / min). While further stirring, 5% by weight aqueous sodium hydroxide solution was added dropwise to adjust the pH to 5. Further, the solid content concentration of the dispersion was measured and adjusted with ion-exchanged water so as to be 16% by weight. Then, the mixture was stirred for 1 hour to obtain a crystalline polyester resin dispersion A-1.

(Production of aqueous dispersion of amorphous resin)
An amorphous resin dispersion E-1 was obtained in the same manner as above except that the crystalline polyester resin A was changed to the amorphous resin E.

(Manufacture of toner)
Crystalline polyester resin dispersion A-1 200 g obtained above, amorphous resin dispersion E-1 100 g, colorant dispersion 8 g, release agent dispersion 10 g, charge control agent dispersion 2 g and deionized water 52 g was placed in a 2 L container, and 150 g of a 0.2 wt% calcium chloride aqueous solution was added dropwise at 30 ° C. over 30 minutes with stirring at 100 r / min (peripheral speed 31 m / min) with a chi-type stirrer. Thereafter, the temperature was increased while stirring, and the temperature was maintained when the temperature reached 50 ° C. At 3 hours, the average particle size reached 5.0 μm. Thereafter, a dilute solution obtained by diluting 4.2 g of anionic surfactant (alkyl ether sulfate, manufactured by Kao Corporation, trade name: “Emar E27C”, solid content: 28 wt%) as deflocculating agent with 37 g of deionized water. Was added. Next, the temperature was raised to 80 ° C., and after stirring for 1 hour from the time when the temperature reached 80 ° C., coalesced particles were formed. Then, the particles were gradually cooled to 20 ° C. and filtered through a 150 mesh (mesh opening 150 μm) wire mesh. Thereafter, suction filtration was performed, and toner particles were obtained through washing and drying processes.

(External addition process)
To 100 parts by weight of the toner particles, hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., trade name: “NAX-50”, number average particle diameter 40 nm) 1.0 part by weight, hydrophobic silica (Nippon Aerosil Co., Ltd.) ), Trade name: “R972”, number average particle diameter 16 nm) 0.6 parts by weight, titanium oxide (manufactured by Teica Co., Ltd., trade name: “JMT-150IB”, number average particle diameter 15 nm) 0.5 weight The part was put into a 10 L Henschel mixer (Mitsui Mine Co., Ltd.) equipped with ST and A0 stirring blades, and stirred at 3000 rpm for 2 minutes to obtain a toner. Table 2 shows the toner evaluation results.

Examples 2-4
Crystalline polyester resin dispersions B-1, C-1, and D-1 were obtained in the same manner as in Example 1 except that the crystalline polyester resin A was changed to crystalline polyester resins B to D, respectively, and toner was obtained. It was. Table 2 shows the toner evaluation results.

Example 5
A crystalline polyester resin dispersion A-2 was obtained in the same manner as in Example 1 except that the organic solvent was changed from ethyl acetate to methyl ethyl ketone to obtain a toner. Table 2 shows the toner evaluation results.

Example 6
After Step 4 of producing the aqueous dispersion of the binder resin of Example 1, a crystalline polyester resin dispersion A-3 was obtained without adjusting the pH, and a toner was obtained. Table 2 shows the toner evaluation results.

Example 7
After Step 4 of producing the aqueous dispersion of the binder resin of Example 1, a 1N aqueous hydrochloric acid solution was dropped to adjust the pH to 2 to obtain a crystalline polyester resin dispersion A-4 to obtain a toner. It was. Table 2 shows the toner evaluation results.

Example 8
Crystalline polyester in the same manner as in Example 1 except that 5% by weight aqueous sodium hydroxide solution was used in place of the aqueous ammonia solution as the neutralizing agent in Step 1 of the production of the aqueous dispersion of the binder resin of Example 1. Resin dispersion A-5 was obtained to obtain a toner. Table 2 shows the toner evaluation results.

Examples 9 and 10
Crystalline polyester resin dispersions A-6 and A-7 were obtained in the same manner as in Example 1 except that the amount of water added was changed and the water / organic solvent ratio was changed as shown in Table 2. Obtained. Table 2 shows the toner evaluation results.

Examples 11 and 12
Crystalline polyester resin dispersions A-8 and A-9 were obtained in the same manner as in Example 1 except that the addition amount of the organic solvent was changed and the binder resin / organic solvent ratio was changed as shown in Table 2. A toner was obtained. Table 2 shows the toner evaluation results.

Examples 13 and 14
The crystalline polyester resin dispersion was the same as in Example 1 except that the ratio of the surfactant added in each step of the production of the aqueous dispersion of the binder resin of Example 1 was changed as shown in Table 2. A-10 and A-11 were obtained to obtain toner. Table 2 shows the toner evaluation results. The total amount of surfactant added was 3 parts by weight with respect to 100 parts by weight of the resin.

Example 15
A crystalline polyester resin-containing dispersion A-12 is obtained in the same manner as in Example 1 except that 80 g of crystalline polyester resin A and 20 g of amorphous polyester resin E are charged instead of 100 g of crystalline polyester resin A of Example 1. A toner was obtained. Table 2 shows the toner evaluation results.

Example 16
A crystalline polyester resin-containing dispersion A-13 is obtained in the same manner as in Example 1 except that 70 g of the crystalline polyester resin A and 30 g of the amorphous polyester resin E are charged instead of the crystalline polyester resin A 100 g of Example 1. A toner was obtained. Table 2 shows the toner evaluation results.

Example 17
A toner was obtained in the same manner as in Example 1 except that 100 g of crystalline polyester B-1 was added in place of 100 g of the amorphous resin dispersion E-1 in the production of the toner of Example 1. Table 2 shows the toner evaluation results.

Example 18
Instead of adding 200 g of crystalline polyester resin dispersion A-1 and 100 g of amorphous resin dispersion E-1 during the production of the toner of Example 1, 100 g of crystalline polyester resin dispersion A-1 and amorphous resin A toner was obtained in the same manner as in Example 1 except that 200 g of Dispersion E-1 was added. Table 2 shows the toner evaluation results.

Comparative Example 1
Example 1 except that 200 g of the crystalline polyester resin dispersion A-1 and 100 g of the amorphous resin dispersion E-1 were changed to 300 g of the amorphous resin dispersion E-1 in the production of the toner of Example 1. In the same manner as above, a binder resin dispersion A-11 was obtained to obtain a toner. Table 2 shows the toner evaluation results.

Comparative Examples 2-5
A crystalline polyester resin dispersion A- was prepared in the same manner as in Example 1 except that the addition amount of the surfactant in each step of the production of the aqueous dispersion of the binder resin of Example 1 was changed as shown in Table 2. 14-17 were obtained and the toner was obtained. Table 2 shows the toner evaluation results. The total amount of surfactant added was 3 parts by weight with respect to 100 parts by weight of the resin.

  From the above results, it can be seen that according to the method of the present invention, an electrophotographic toner excellent in low temperature fixability, charging stability under high temperature and high humidity, and heat resistant storage stability can be obtained.

  The electrophotographic toner obtained by the method of the present invention is excellent in low-temperature fixability, high-temperature and high-humidity charging stability and heat-resistant storage stability, and is therefore used in electrophotographic methods, electrostatic recording methods, electrostatic printing methods, etc. It can be suitably used as an electrophotographic toner.

Claims (6)

An electrophotographic toner manufacturing method comprising particles obtained by fusing agglomerated particles obtained by agglomerating an aqueous dispersion of a binder resin for toner, wherein the binder resin contains a crystalline polyester resin, The aqueous dispersion is obtained through the following steps 1 to 4, and 80 to 100% by weight of the total addition amount of the surfactant is mixed in the steps 2 and 4, and the surfactant is mixed in the steps 2 and 4. A method for producing an electrophotographic toner, wherein the weight ratio of the added amount of the agent is 10/90 to 40/60 as the weight of the surfactant added in Step 2 / the weight of the surfactant added in Step 4.
Step 1: A step of mixing at least a binder resin, an organic solvent and a neutralizing agent to obtain a mixture.
Step 2: A step of mixing at least water and a surfactant with the mixture obtained in Step 1 to obtain a resin dispersion.
Step 3: A step of obtaining an aqueous dispersion of a binder resin by removing the organic solvent from the resin dispersion obtained in Step 2.
Step 4: A step of mixing a surfactant with the aqueous dispersion obtained in Step 3.   The crystalline polyester resin includes an alcohol component containing 70 mol% or more of an aliphatic diol having 2 to 14 carbon atoms, and a carboxyl containing 80 mol% or more of an aliphatic dicarboxylic acid compound or aromatic dicarboxylic acid having 8 to 12 carbon atoms. The method for producing an electrophotographic toner according to claim 1, which is obtained by condensation polymerization of an acid component.   The method for producing an electrophotographic toner according to claim 1, wherein the content of the crystalline polyester resin in the binder resin is 65% by weight or more.   The electrophotography according to any one of claims 1 to 3, wherein in step 1, the weight ratio of the binder resin to the organic solvent (binder resin / organic solvent) is 1 / 1.5-1 to 0.03. Of manufacturing toner.   5. The method for producing an electrophotographic toner according to claim 1, wherein in step 2, a weight ratio of water to an organic solvent (water / organic solvent) is 70/30 to 98/2. Organic solvent is acetic acid esters, method of manufacturing toner for electrophotography according to any one of claims 1-5.